Using human cell lines, the ITIM-receptor PECAM-1 was found to antagonize IM-induced apoptosis [34], but genetic depletion of PECAM-1 in a retroviral model of CML-like disease showed no effect on CML myeloid progenitor viability or clonogenic potential in vitro [33]. Here, PECAM1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.